When you're not from Austria or Germany you've probably never heard about Erich Kästner in your life. Or so you might be thinking, just reading the name. I'm pretty sure you've come across some of his books one way or another, most likely through a movie adaption. But first things first, so I'll tell you a bit more about him.
Kästner was a German author, best known for his children's literature, using humour to expose human folly and social ills. His work includes books such as Emil And The Detectives, with which he first earned widespead fame, The Flying Classroom and Lottie And Lisa.
Especially the Emil books (yes, there were more books about those children detectives to follow) played an important role in popularising the sub-genre of "Children Detectives", later taken up by other writers of children's books such as Enid Blyton.
I believe I read almost all of his books several times as a kid and needless to say I loved them.
Still not sure how you may know any of his works?
You mightn't have heard of Lottie And Lisa before, but remember a movie called The Parent Trap. This Disney movie is based on Erich Kästner's book and it's been adapted for the movies several times. The one with Lindsey Lohan is the newest, but the one that came out in the 60s had a lot more charm if you ask me.
You could say that if it hadn't been for Walt Disney, Kästner would have never gained international popularity (despite the sad fact that you'll probably link the movie only to Disney and not the author himself).
As far as English translations of his many children's books are concerned, only a selected few of his books (see above) came out in English. Yet, if you want to read one of them you'd probably have a hard time finding bookstores that still sell them.